Complexity of mitochondrial dynamics in neurons and its control by ADP produced during synaptic activity.

This review focuses on different aspects of dynamics of mitochondria in neuronal cytoplasm which play an important role in the life and fate of neurons. It starts with description of the energy supply in the brain; considers the typical patterns of mitochondrial movements; relates them to the neuronal activity and in particular at the synapses; extends to the analysis of the origin of local ATP changes in the cytoplasm; considers main features of motor-assisted movements of mitochondria and their role in determining a transport velocity; describes the measurements of ATP gradients in neuronal processes and relates them to spatial variations in the mobility of mitochondria that occur in the vicinity of synapses due to the local ADP increases; considers the influence of hypoxia and intracellular signalling pathways on mitochondria movements. Finally, the recent views on the mechanisms and possible functional role of mitochondrial network as a whole in neurons are discussed and unresolved issues and future perspectives in this field of research are delineated.